| Tea is one of the important woody crops in China. The trauma which from the pickings, prunings, and feedings of chewing insects have an significant influence on the growth of the plant and the quality of tea. Up to now, a little information is available about the molecular biology of the trauma response of tea plant. In order to better understand the molecular changes about the trauma response of tea plant, we employed RNA-seq to investigate transcriptomes of tea leaves after injuring them at different time, and then the sequencing results were analyzed. The main results are as follows:1. A total of 11.73 Gb high quality reads was obtained in the result of RNA-seq. After de novo assembling,129610 unredundant transcripts were obtained. The average length of transcripts is 1256.94, and N50 is 1780 bp.2. Through comparing with several databases,100,834 sequences of all transcripts accounted for 77.80% of the total number of transcripts were annotated, and still a number of 28776 transcript accounted for 22.20% of the total number of transcripts were not annotated, which may be the special transcripts of tea plant.3. The result of differential expression analysis showed that the number of total DET was 19214. Compared with 0h,4 DET sets (3 h vs.0 h,6 h vs.0 h,12 h vs.0 h,24 h vs.0 h) were 6357,6299,6865,4894 DETs, respectively. The expression pattern analysis of transcription factor family showed that:a total of 13064 transcription factors transcript (3107 belonged to DET) belonged to 56 transcription factor families. This revealed that the number of transcription factors in tea plants was significantly more than that of Arabidopsis thaliana. The analysis results showed that the transcription factor families appeared a process of reprogramming in the trauma response of tea plant.4. KEGG annotation showed that:a large number of DETs involved in signaling pathways (such as calcium signaling pathways, and plant hormone signal transduction pathways) were found in this transcriptome. However, the transcript of several important enzyme of JA synthesis were not showing differentially expressed. This implies that the increase of JA content caused by the trauma of tea plant may not be related to the level of transcription of these genes, may be related to post transcriptional and protein levels change relations more closely, or still need further research for other reasons. More important, the number of DETs wich involved in secondary metabolites synthesis is 594, only less than that of the metabolic pathway. The DETs of key enzymes in four important secondary metabolites (flavonoid biosynthesis pathway, caffeine synthesis pathway and terpenoid biosynthetic pathway) were up-regulated. This indicates that the secondary metabolites play an important role in the response of the trauma response of tea plant.5. CsERFa gene belonged to ERF family which is an important transcription factor family in plant responsing to stress, This gene was continuously up-regulated in the process of trauma. The ORF of CsERF gene was 708bp, and encoded a cytosolic protein containing 235 amino acids. CsERFa protein has the typical structers of AP2 domain:1 alpha helix and 3 beta strands. The transgenic expression vector was constructed, and the transgenic tobacco experiment was done.In summary, we used high-throughput sequencing technology to analyze the transcriptome of the trauma response of tea plant. Functional annotation and classification of tea plant transcript were performed, and the DETs, the expression pattern of transcription factor families, signal transduction pathways and secondary metabolic pathways of the trauma response were studied. In addition, the significant DET was analyzed in detail. The results greatly enriched the data resources of the tea transcriptome, and provided a foundation for the development of tea plant in the fields of genomics and molecular biology, and the study on the mechanism of plants, especially woody plants in response to trauma. |
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